[Objective] Through studying mRNA expression levels of circadian gene pdp（Pyruvate dehydrogenase phosphatase） in Locusta migratoria under different conditions to reveal molecular mechanisms of rhythm of Locusta migratoria.[Methods] The prototype of the pdp gene and design primers were found out based on the database of Institute of Zoology,Chinese Academy of Sciences.Using aggregated locust head cDNA as templates,the complete sequence of the gene pdp was obtained.By dividing a day（24 hours） into eight points,fixed-point samples were taken,and the pdp gene expression levels at different time periods were determined by using qRT-PCR;and the pdp gene expression levels with different treatment were also determined.[Results] The circadian gene pdp in Locusta migratoria changed slightly with different treatment.[Conclusion] The study had extremely realistic significance for understanding the rhythm and population characteristics of Locusta migratoria as well as effective insect-resistant.
